u/Cmdr-reigns

I’m being told by my union chairman that after 0700 the fray considers it the next day if you work past it. I work midnights so my normal schedule is 2300-0700… he says that on my 5th day of service that if I stay past 0700 the fray considers it having worked my 6th day. Is this true? Is there someone somewhere I can call to verify?